Welsh councils have stockpiled a record amount of grit in a bid to tackle the type of transport chaos seen during recent Arctic winters.

Brutally cold conditions in two of the past three winters have seen many Welsh roads rendered unpassable as grit supplies struggled to cope with prolonged periods of icy temperatures.

But local government minister Carl Sargeant has revealed Wales will enter the forthcoming winter with a stock of 243,000 tonnes of road salt – more than 100,000 tonnes more than the amount at the equivalent point in 2010.

That year, councils were forced to order an extra 12,000 tonnes of grit from Sweden and spend £7m intended to pay for fixing roads on boosting supplies after a record-breaking cold snap.

As temperatures plunged as low as -20C over the Christmas period, councils were forced to share salt supplies and prioritise key routes. Many smaller roads remained completely blocked for several days.

The fallout from the shortages developed into a political row as recriminations flew about where the blame for the chaos should lie.

Around 200,000 tonnes of salt were used in each of the cold winters of 2009/10 and 2010/11.

Problems were avoided during last year’s largely mild winter, but moves have now been made to ensure there can be no repeat of the previous year’s fiasco.

New grit storage facilities have been established in Merthyr Tydfil, Blaenau Ffestiniog and Queensferry, while extra centres in Llanidloes and at a location in North Wales will be set up during the course of the season, creating room for 40,000 more tonnes than could be stored two years ago.

Mr Sargeant said: “Everybody appreciates that the winter weather in Wales can be unpredictable.

“Last winter, which was relatively mild, followed two severe winters with the combination of extremely low temperatures and widespread snowfall causing disruption to services across the country.

“The Welsh Government and the WLGA have continued to work closely throughout the year to ensure that there are sufficient salt stocks available across the country at the start of the winter maintenance season.

“This will ensure that we’re fully self-sufficient throughout the winter period without the need to re-stock or introduce salt conservation measures.”

Councils across Wales have also been given new guidance to make sure grit is used efficiently.

Anthony Christopher, the WLGA’s transport spokesman, said: “Local authorities have worked collaboratively on the issue of salt stocks and have agreed on each authority maintaining stock levels that should meet their own needs through the winter. Alongside the Welsh Government’s strategic stock holdings and mutual aid agreements between authorities this also gives us greater resilience at a national level.

“We believe we enter the winter period well-prepared, although any prolonged periods of snow inevitably results in stock holdings running down quickly.

“Ongoing discussions with the main suppliers to Welsh authorities have been aimed at ensuring restocking takes place in an orderly way over the winter period.”